Humidity controllers which controls humidity using an adsorbent have been known. Patent Document 1 discloses a humidity controller which includes an adsorption heat exchanger carrying an adsorbent on its surface.
The humidity controller described in Patent Document 1 is provided with a refrigerant circuit which includes two adsorption heat exchangers. The refrigerant circuit alternately performs an operation in which the first adsorption heat exchanger serves as a condenser and the second adsorption heat exchanger serves as an evaporator, and an operation in which the second adsorption heat exchanger serves as a condenser and the first adsorption heat exchanger serves as an evaporator. In the adsorption heat exchanger serving as an evaporator, moisture in the air is adsorbed by the adsorbent. In the adsorption heat exchanger serving as a condenser, the moisture is desorbed from the adsorbent and is released in the air.
According to the humidity controller described in Patent Document 1, one of the air currents which have passed through the adsorption heat exchangers is supplied into a room and the other air current is exhausted to the outside. For example, in the humidity controller during the dehumidification operation, the flow path of the air in the casing is formed such that the air which has passed through one of the first and second adsorption heat exchangers that serves as an evaporator is supplied into a room, and the air which has passed through the adsorption heat exchanger that serves as a condenser is exhausted to the outside (see FIG. 5 and FIG. 6 in Patent Document 1).
Further, the humidity controller described in Patent Document 1 ventilates a room. The humidity controller during the dehumidification operation dehumidifies the outdoor air taken therein, using the adsorption heat exchanger serving as an evaporator, and supplies the dehumidified air into a room, and exhausts the room air taken therein to the outside together with moisture desorbed from the adsorption heat exchanger serving as a condenser. On the other hand, the humidity controller during the humidification operation humidifies the outdoor air taken therein, using the adsorption heat exchanger serving as a condenser, and supplies the humidified air into a room, and dehumidifies the room air taken therein, using the adsorption heat exchanger serving as an evaporator, and exhausts the dehumidified room air to the outside.